The Government has spent more than a quarter of a million dollars testing and polling its Unite Against Covid-19 campaign, including its "brand effectiveness".
The Act Party says it shows the Government is focused on popularity over science.
Meanwhile, the Government says the research was used to ensure its campaigns were "effective and getting cut-through", and to understand how the public felt about what was being asked of them.
Information provided to the Act Party showed the Department of the Prime Minister and Cabinet (DPMC) spent $252,945 on research including opinion polling and focus groups relating to the public campaign Unite Against Covid-19.
This included "testing messaging and concepts and using research to understand how New Zealanders were feeling in relation to Covid-19, and the motivations and barriers to the associated public health behaviours required of them".
It included a the Sentiment & Behaviours Benchmark survey released this month around how to keep New Zealanders engaged with the campaign Unite Against Covid-19.
A DPMC Covid-19 Response Group spokesperson said focus groups and surveys helped ensure messages and campaigns were "effective and getting cut-through".
The research was also used to understand how New Zealanders were feeling about Covid-19, and the public health measures being asked of them.
Act leader David Seymour said while Prime Minister Jacinda Ardern had always said the Government would "listen to the science", the polling showed it was more interested in public perception.
"Many times Act has asked the Government to share the information it uses to make decisions, and the framework for future decisions with the public.
"We asked them to treat New Zealanders like adults, bringing us into their confidence.
"We now know that they don't want to release a framework so they can be guided by focus groups. The Government has been slow to release the advice, including the Skegg Report. Are they focus grouping the findings before it's released?"
Seymour questioned how much other decisions such as on mask-wearing, how long it took the Government to enact the transtasman travel bubble and around RSE workers were based on polling and focus groups.
"One has to ask, is the real reason we do not have plan to get our way of life back is that the Government is still focus grouping it."
A spokeswoman for Ardern declined to comment.
University of Auckland political scientist Dr Lara Greaves said she was not so concerned about polling in itself, but rather the type of polling.
The latest survey listed "brand effectiveness" as one of the five objectives.
"We can totally understand why they might be testing the messaging and context, and a range of Government agencies appear to be doing this, including the Ministry of Health on vaccine hesitancy.
"But what I am concerned about with the [DPMC work] is it is firmly in market research and not an example of a great survey."
The latest survey was not peer-reviewed nor was there much detail to be able to assess the quality of the work, she said.
"It is a challenge of the pandemic, understanding social behaviours because ultimately peoples' opinions will determine how our response works or fails.
"But where there is research being used with objectives like brand effectiveness it gets a bit tricky. I would have liked to have seen it more rooted in social science and health psychology."
Epidemiologist Dr Michael Baker said generally speaking when conducting a public health response of this scale and seeking to change peoples' behaviours there was a need to engage with the public for it to be successful.
Given the billions being spent on the Covid-19 response and wider costs Baker said there was an argument for more surveys and research to be conducted.